When true-breeding, or homozygous, individuals that differ for a certain trait are crossed, all of the offspring will be heterozygous for that trait. If the traits are inherited as dominant and recessive, the F1 offspring will all exhibit the same phenotype as the parent homozygous for the dominant trait .
What is the result of a cross between one homozygous dominant parent and one homozygous recessive parent?
For example, if one parent is homozygous dominant (WW) and the other is homozygous recessive (ww), then all their offspring will be heterozygous (Ww) and possess a widow’s peak .
What is the probability that a homozygous dominant parent will have an offspring that is homozygous recessive?
If a homozygous dominant is crossed with a heterozygote, the probability that an offspring will be homozygous recessive is 0% . 10. If two heterozygotes are crossed, the probability that an offspring will be homozygous recessive is 25% or 0.25. Homozygous dominant: 25% or 0.25.
What is homozygous recessive and homozygous dominant?
An organism can be homozygous dominant, if it carries two copies of the same dominant allele , or homozygous recessive, if it carries two copies of the same recessive allele. Heterozygous means that an organism has two different alleles of a gene. ... People with CF are homozygous recessive.
What is the probability that a cross between parents who are both homozygous recessive for a trait will have offspring that are homozygous recessive for that trait?
To summarize, recessive alleles will only appear in a phenotype when the individual is homozygous. If both parents are homozygous and recessive for a trait, 100% of their offspring will also express the trait.
What is the percentage of a homozygous dominant offspring?
| PARENT GENOTYPES OFFSPRING PHENOTYPES | pure (homozygous) dominant x anything 100% of offspring with dominant trait | hybrid x homozygous recessive 50% dominant trait, 50% recessive trait | hybrid x hybrid 75% with dominant trait & 25% with recessive trait | homozygous recessive x homozygous recessive 100% recessive trait |
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Is FF heterozygous or homozygous?
| Genotype Phenotype | F F Homozygous dominant No cystic fibrosis (Normal) | F f Heterozygous Carrier (has no symptoms but carries the recessive allele) | f f Homozygous recessive Cystic fibrosis (has symptoms) |
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What are odds of having a homozygous recessive or heterozygous offspring?
The Punnett square below makes it clear that at each birth, there will be a 25% chance of you having a normal homozygous (AA) child, a 50% chance of a healthy heterozygous (Aa) carrier child like you and your mate, and a 25% chance of a homozygous recessive (aa) child who probably will eventually die from this ...
Is AA homozygous or heterozygous?
If an organism has two copies of the same allele, for example AA or aa, it is homozygous for that trait. If the organism has one copy of two different alleles, for example Aa, it is heterozygous. Keep in mind that an organism can’t simply be ‘homozygous,’ period.
Is BB heterozygous or homozygous?
An organism with two dominant alleles for a trait is said to have a homozygous dominant genotype. Using the eye color example, this genotype is written BB. An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype.
How do you know if someone is homozygous or heterozygous?
If an organism has identical genes on both chromosomes, it is said to be homozygous . If the organism has two different alleles of the gene it is said to be heterozygous.
What is an example of a homozygous recessive combination?
A homozygous recessive allele combination contains two recessive alleles and expresses the recessive phenotype. For example, the gene for seed shape in pea plants exists in two forms , one form (or allele) for round seed shape (R) and the other for wrinkled seed shape (r).
Is TT homozygous dominant?
| Genotype Definition Example | Heterozygous One dominant allele and one recessive allele Tt | Homozygous dominant Two dominant alleles TT | Homozygous recessive Two recessive alleles tt |
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What is homozygous condition?
Homozygous
Homozygous is a genetic condition where an individual inherits the same alleles for a particular gene from both parents .
How is a recessive trait expressed?
When a trait is recessive, an individual must have two copies of a recessive allele to express the trait. Recessive alleles are denoted by a lowercase letter (a versus A). ... If one parent is heterozygous (Ss) and the other is homozygous recessive (ss), then half of their offspring will have a smooth chin.
Is PP genotype or phenotype?
A simple example to illustrate genotype as distinct from phenotype is the flower colour in pea plants (see Gregor Mendel). There are three available genotypes, PP ( homozygous dominant ), Pp (heterozygous), and pp (homozygous recessive).
